Great Webcomic Crossover Wars of 2007
From Jenny Everywhere Wiki
The Great Webcomic Crossover Wars of 2007 were an event which some parties in the Collapsed Cosmos suggested had been the cause of the collapse of the Multiverse. However, this was only one theory. (PROSE: The Hermetic Garbage of Jenny Everywhere)
Behind the scenes
This presumably refers to the events of The Crossing Over Worlds.